Spectra Of Rhodamine 6G Research Articles

Spectral-Kinetic Properties of Laser Dyes in Active Elements on the Basis of Sol-Gel Matrices

The absorption and photoluminescence spectra as well as the photoluminescence lifetimes of laser dyes (Phenylamine 430, Rhodamine 6G, Rhodamine 6G zwitterion, Rhodamine 4C, and Rhodamine 101) in new matrices are studied. These matrices represent the hybrid of two types of porous glasses (microporous and sol-gel glass). Chemical transformations of the dye molecules in the matrices are not found. The dye dimers mentioned above are also absent for concentrations up to 10-4 M. The luminescence efficiencies of the dyes in the matrix and in the ethanol solutions are compared. The difference in concentration dependences of the photoluminescence spectrum of Rhodamine 6G in the matrix and ethanol solution is found and discussed. The collective emission of the dyes in new matrices is observed at a power density of exciting radiation of ∼1025 cm-2s-1 and a concentration of ∼10-4 M. The energies and collective emission spectra of the dyes in the matrix are compared with those in the solutions.

On-Column Surface-Enhanced Raman Spectroscopy Detection in Capillary Electrophoresis Using Running Buffers Containing Silver Colloidal Solutions

Direct on-column surface-enhanced Raman spectroscopy (SERS) detection is demonstrated in capillary electrophoresis (CE). Distinctive SERS spectra of two test compounds, riboflavin and Rhodamine 6G, are obtained in 100 microm i.d. fused-silica capillaries under CE conditions using running buffers that contain silver colloidal solutions. Detection is performed using an unmodified commercial Raman spectrometer in a confocal microscope mode of operation. The effects of laser power, wavelength, spectra acquisition time, silver colloidal concentration, and applied voltage (i.e., flow rate) on the quality of SERS spectra are evaluated. Using laser powers of 17 mW (at the sample) at 515 nm and employing 1 s spectral acquisition times, spectra with bands exhibiting signal-to-noise ratios greater than 10 could be obtained for 1.0 x 10(-6) M riboflavin and very low nanomolar concentrations of Rhodamine 6G. This was accomplished without optimization of silver colloidal solution compositions and by using a low-throughput spectrometer. Incorporation of the colloidal solutions into running buffers is shown to have little effect on the separation of the test compounds as monitored using a laser-induced fluorescence instrumental scheme. However, SERS spectra degrade if the capillary is not rinsed between experiments. Riboflavin and Rhodamine 6G spectra are obtained on-the-fly for actual CE separations. In the case of the latter solute, the injected quantity was approximately 90 amol.

Construction of A Ccd Multichannel Fiberoptic Spectrometer and Its Application

Abstract A multichannel spectrometer was constructed with a linear CCD and a fiber-optic probe, which can perform in situ and quick spectrum measurement. Being linked to a PC computer, this spectrometer is especially suitable for dynamical process monitoring. The application of this instrumentation in the research of peroxyoxalate chemiluminescence has revealed the wavelength shift of the light emitting spectrum of rhodamine 6G during the chemiluminescent reaction.

Approach to Single Molecule Detection Using Surface-Enhanced Resonance Raman Scattering (SERRS): A Study Using Rhodamine 6G on Colloidal Silver

We have measured surface-enhanced resonance Raman scattering (SERRS) spectra of rhodamine 6G (R6G) at concentrations as low as 8 × 10−16 M in colloidal silver solution activated by NaCl ions. The spectra were measured with a fiber-optic probe using the 514.5-nm argon-ion laser line as excitation source and a charge-coupled-device (CCD) detection system. The correlation of SERRS photo counts and R6G concentration was found to be linear between 8 × 10−11 and 8 × 10−14 M concentrations within our experimental accuracy. Experiments conducted with small scattering volumes show that fewer than 100 R6G molecules are sufficient to give rise to a SERRS spectrum with reasonable signal-to-noise ratio. These results demonstrate that in certain cases SERRS can achieve detection limits comparable to those for fluorescence spectroscopy, and at the same time provides higher structural specificity than fluorescence. The possibilities of using SERRS for single molecule detection are discussed.

Wavelength dependence of phase conjugate reflectivity in absorbing media and thermal grating studies by four wave mixing

The development of optical phase conjugation using thermally formed gratings in absorbing media, especially the dye solutions, has besides the high efficiencies, many other characteristics which are worthy of study. Here the wavelength dependence of phase conjugate reflectivity in relation to absorption spectrum of rhodamine-6G and rhodamine-B in water, methanol and ethanol is reported. Further the Bragg condition has been verified for the dominant diffracted beam which shows that the thermal grating behaves like an optically thick grating.

Coherent amplification in fluorescent dye solutions. II. The inverse pre-resonance Raman spectrum of rhodamine 6G

Abstract Inverse pre-resonance Raman spectra of rhodamine 6G in solution in methanol have been recorded over the concentration range 10−1 to 10−4 mol l−1. The solute and solvent transitions are found to display perfectly normal lorentzian profiles over the whole of this concentration range. Intensities and depolarization ratios of the pre-resonance Raman features are recorded. It is shown that the spectra arise from monomeric rhodamine 6G molecules in the singlet electronic ground state and the relative merits of the CARS and inverse Raman methods for recording resonance Raman spectra are discussed.

Concentration effects in the spectra of rhodamine 6G in rigid matrices

Levshin et al. [i] studied concentration effects of the luminescence and absorption spectra of rhodamine 6G in frozen ethanol solutions at--175~ With increasing dye concentration from 10 -5 to 5"10 -2 mole/liter, these authors observed a shift in the luminescence spectrum towards greater wavelengths by 2000 cm -I and growth of a second maximum in the absorption spectrum shifted towards shorter wavelengths by 1300 cm -I

Effect of intermolecular interactions on the electronic spectra of rhodamine 6G

Effect of intermolecular interactions on the electronic spectra of rhodamine 6G